In an age in which the imperative to reuse and recycle is stronger than ever - not in terms of making pop music, but rather with an eye on the future of the planet - it's good to learn that this record was apparently recorded on acoustic instruments in Iceland and then reworked on solar-powered laptops in a raw food commune in Hawaii.

This certainly sounds plausible when you hear Riceboy Sleeps, the debut release from Sigur Rós's singer Jón Þór Birgisson (usually known as Jónsi) and his boyfriend Alex Somers, who have previously staged art shows under the same name. Earlier this year, their track Happiness featured on the compilation Dark Was the Night, alongside music by the likes of Arcade Fire, Sufjan Stevens, Beirut and Bon Iver, signalling that something special was bubbling up. And while ecological or environmental metaphors tend to be wrung dry writing about Sigur Rós, with a particular tendency, given that they're Icelanders, to invoke melting glaciers and geysers, it's hard to avoid the same here: tracks of nine minutes or longer slowly coalesce, like time-lapse images of snowflakes forming or moss growing. Jónsi's soaring voice is absent, but a celestial choir features alongside occasional animal grunts and chirrups.

It's an ambient record in the best traditions of Brian Eno or Harold Budd, although the gentle grandeur of a track such as Daníell in the Sea might otherwise bring to mind Mahler. Either way, this is beautifully fragile music, not disposable but built to last.